Since 1995, the State Board of Education can only reject textbooks if they contain "factual errors" or if they don't include the items required by the state's Texas Essential Knowledge and Skills (TEKS) curriculum standards. Books that include fewer than half the TEKS but are otherwise okay are put on a "non-conforming" list; books with most or all of the TEKS are "conforming," and local districts can use their state textbook money on either. The SBOE can adopt a book with "factual errors" and give the publisher a chance to correct them.
The 1995 rules were a legislative attempt to sober up the textbook-adoption circus. However, the SBOE may still pass a resolution "which expresses an opinion related to specific textbooks or which expresses concerns as to the appropriateness of specific textbooks for certain ages or populations." They can only do this after a book is on the conforming or non-conforming list. However, publishers are still leery enough of the SBOE's opinion -- and the chilling effect it has on local districts' book purchases -- that many have chosen to withdraw titles that the board finds objectionable.
Chapter 31 of the state Education Code includes what used to be the criteria for textbook adoption, and what are now standards for the SBOE's "opinion" resolutions. Some highlights:
Theories (you know, like evolution) should be "clearly distinguished from fact."
Texts should "promote citizenship, patriotism, understanding of the essentials and benefits of the free enterprise system, respect for recognized authority, and respect for individual rights." They should not "encourage or condone civil disorder (or) social strife." (Does that mean the American Revolution was a good thing or a bad thing?) A subsequent section defines "free enterprise" -- capitalism and private property rights -- in case SBOE members aren't sure.
Texts "should present positive aspects of the United States and its heritage" and should give "balanced and factual treatments" of "contrasting points of view" about political and social events. The code is silent about what makes for a legitimate "contrasting point of view" -- slavery apologists, Holocaust deniers, and flat-earthers are all technically entitled to their fair hearing in kids' schoolbooks.
Texts should "treat divergent groups fairly without stereotyping and reflect the positive contributions of all individuals and groups to the American way of life." However, they should "not encourage life-styles deviating from generally accepted standards of society," should include both "traditional and contemporary roles of men, women, boys, and girls," and "should provide an objective view of cultural confluence" -- whatever that means.